Nerve Growth Factor Potentiates p53 DNA Binding but Inhibits Nitric Oxide-Induced Apoptosis in Neuronal PC12 Cells

Previous studies have shown that in neuronal cells the developmental phenomenon of programmed cell death is an active process, requiring synthesis of both RNA and protein. This presumably reflects a requirement for novel gene products to effect cell death. It is shown here that the death of nerve growth factor-deprived neuronal PC12 cells occurs at the same rate as that of rat sympathetic neurons and, like rat sympathetic neurons, involves new transcription and translation. In nerve growth factor-deprived neuronal PC12 cells, a decline in metabolic activity, assessed by uptake of [3H]2-deoxyglucose, precedes the decline in cell number, assessed by counts of trypan blue-excluding cells. Both declines are prevented by actinomycin D and anisomycin. In contrast, the death of nonneuronal (chromaffin-like) PC12 cells is not inhibited by transcription or translation inhibitors and thus does not require new protein synthesis. DNA fragmentation by internucleosomal cleavage does not appear to be a consistent or significant aspect of cell death in sympathetic neurons, neuronal PC12 cells, or nonneuronal PC12 cells, notwithstanding that the putative nuclease inhibitor aurintricarboxylic acid protects sympathetic neurons, as well as neuronal and nonneuronal PC12 cells, from death induced by trophic factor removal. Both phenotypic classes of PC12 cells respond to aurintricarboxylic acid with similar dose-response characteristics. Our results indicate that programmed cell death in neuronal PC12 cells, but not in nonneuronal PC12 cells, resembles programmed cell death in sympathetic neurons in significant mechanistic aspects: time course, role of new protein synthesis, and lack of a significant degree of DNA fragmentation.

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Inhibitors of nitric oxide synthase attenuate nerve growth factor-mediated increases in choline acetyltransferase expression in PC12 cells

Journal of Neurochemistry ◽

10.1046/j.1471-4159.2002.00854.x ◽

2002 ◽

Vol 81 (3) ◽

pp. 624-635 ◽

Cited By ~ 17

Author(s):

Bettina E. Kalisch ◽

Nicholas A. Bock ◽

Wanda L. Davis ◽

R. Jane Rylett

Keyword(s):

Nitric Oxide ◽

Nerve Growth Factor ◽

Growth Factor ◽

Nitric Oxide Synthase ◽

Pc12 Cells ◽

Choline Acetyltransferase ◽

Nerve Growth ◽

Oxide Synthase

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Nitric Oxide Synthase Inhibitors Modulate Nerve-Growth-Factor Mediated Activation of Akt

ISRN Cell Biology ◽

10.5402/2012/847974 ◽

2012 ◽

Vol 2012 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Cheryl L. Cragg ◽

Janet C. MacKinnon ◽

Bettina E. Kalisch

Keyword(s):

Nitric Oxide ◽

Nerve Growth Factor ◽

Growth Factor ◽

Map Kinase ◽

Pc12 Cells ◽

Cell Lines ◽

Nerve Growth ◽

Akt Phosphorylation ◽

Map Kinase Pathway ◽

Kinase Pathway

Nitric oxide (NO) modulates nerve-growth-factor- (NGF-) mediated signaling and gene expression. In the present paper, the role of NO in NGF-mediated Akt activation in PC12 and IMR32 cells was investigated. Cells were treated with NGF (50 ng/mL) in the presence or absence of NO synthase (NOS) inhibitors and Akt phosphorylation assessed by western blot analysis. In both cell lines, Akt was phosphorylated within 15 min of NGF treatment. In PC12 cells, this level of phosphorylation was sustained for 60 min, while in IMR32 cells, the activation decreased after 30 min of NGF treatment. The nonselective NOS inhibitor Nω-nitro-L-arginine methylester (L-NAME; 20 mM) had no effect on NGF-mediated Akt phosphorylation in PC12 cells but in combination with NGF, the iNOS selective inhibitor s-methylisothiourea (S-MIU; 2.0 mM) maintained Akt phosphorylation up to 2 h. In IMR32 cells, both L-NAME and S-MIU prolonged the activation of Akt. Pretreatment with 50 μM U0126, a MAP kinase pathway inhibitor, also increased the activation of Akt in both cell lines. These data suggest that NO modulates the duration of phosphorylation of Akt in response to NGF and that this effect may, in part, be mediated by the effects of NO on the Ras-MAP kinase pathway.

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